Re: cvs commit: src/sys/dev/bge if_bge.c

From: Jung-uk Kim <jkim_at_FreeBSD.org>
Date: Tue, 19 Sep 2006 15:35:06 -0400
On Tuesday 19 September 2006 03:04 pm, Peter Jeremy wrote:
> On Tue, 2006-Sep-19 14:30:59 -0400, Jung-uk Kim wrote:
> >On Tuesday 19 September 2006 01:52 pm, John Baldwin wrote:
> >> Which I'm about to kill hopefully.  Please let's fix this the
> >> right way and not hack it any further.
> >
> >Sure, no problem.  But I don't think we can DTRT on -STABLE
> > without breaking API.  Can we?
>
> I've had a quick look into this problem because I extensively use
> VLANs on a bge and discovered that I no longer have VLAN tag
> details (which makes packet tracing a nuisance).
>
> As far as I can see, there is nothing preventing bpf_tap() and
> bpf_mtap2() being doctored to undo the VLAN detagging so that
> bpf_filter() is passed a mbuf chain that looks like an 802.1Q
> ethernet frame:  Dummy up an mbuf (as bpf_mtap2() does) that
> contains the MAC addresses from the incoming data followed by
> the 802.1Q packet type and tag information, with m_next pointing
> to the byte after the MAC addresses in the original data.

Why don't we just fake it up from ether_input() and pass it to 
BPF_MTAP() instead of 'teaching' bpf?  I think it is more logical 
thing to do.

Jung-uk Kim
Received on Tue Sep 19 2006 - 19:35:26 UTC